#ifndef HF_SUBJECT_H
#define HF_SUBJECT_H

#include <memory>
using namespace std;

#include <hf_observer.h>
namespace HeadFirstS
{
    class HF_Subject
    {
    public:
        virtual void registerObserver(HF_Observer* o) = 0;
        virtual void removeObserver(HF_Observer* o) = 0;
        virtual void notifyObservers() = 0;
    };
}
#endif // HF_SUBJECT_H
